1. Field of the Invention
The present invention relates to an engine support structure of a motorcycle which is suitable for a motorcycle of an American-type or other type.
2. Description of Background Art
Conventionally, as an engine support structure of a motorcycle of this type, there has been known an engine support structure which generally and widely adopts a technique in which an engine is fastened to a vehicle body frame by mounting a holding member on a vehicle body frame and by inserting a bolt into the holding member and a mounting portion of the engine (See, for example JP-UM-A-58-33390 (FIG. 1)).
Further, as another engine support structure, there has been proposed an engine support structure which adopts a technique in which a pipe is laterally (horizontally) extended between a pair of down tubes and a stay is fastened to the pipe using a bolt, and an engine is mounted on the stay (for example, see JP-UM-A-3-5590 (FIG. 4 to FIG. 6).).
However, in JP-UM-A-58-33390 (FIG. 1), in assembling the engine, it is necessary to align a fastening hole with the holding member while supporting the engine and hence, there has been a demand for reducing the difficulty of the assembling operation of the engine.
On the other hand, in JP-UM-A-3-5590 (FIG. 4 to FIG. 6), in assembling the engine, it is necessary to insert the bolt vertically from below to above. Further, as parts for connecting the engine to down tubes, two parts such as the pipe and the stay are necessary and hence, the number of parts is increased and also the structure of the engine assembling becomes complicated.
Further, in JP-UM-A-58-33390 (FIG. 1) and JP-UM-A-3-5590 (FIG. 4 to FIG. 6), in the vicinity of the mounting portion of the engine, a head of the bolt and a nut which fixedly mount the engine on the vehicle body frame are exposed on a side surface. However, by making the head of the bolt and the nut hardly observed from the outside, it is possible to enhance the appearance of the motorcycle.